Rui Okubo

is a Japanese kickboxer. He is the former Krush Flyweight (-51kg) champion and the 2024 K-1 Super bantamweight (-55 kg) World Tournament runner-up.

As of April 2024 he was the 10th ranked strawweight (-54 kg) kickboxer in the world by Combat Press.

Biography and career Krush As an amateur Okubo amassed a record of 145 wins, 18 losses, 3 draws and captured over 40 titles. During 2021, his last year of competition before turning professional, Okubo won the two most prestigious titles of Japanese amateur kickboxing, the Japan Cup in March and the K-1 Koshien tournament in August. He won four fights in one day during both tournaments. His Koshien success secured him a professional debut with the K-1 promotion. He was awarded the Best Amateur Athlete Award at the 2021 K-1 Awards Show.

Okubo made his professional debut on February 27, 2022, at K-1 World GP 2022 Japan against Shohei Nishibayashi. He won the fight by unanimous decision.

For his second professional fight, Okubo was invited on the exceptional card THE MATCH 2022 at the Tokyo Dome, on June 19, 2022, where he faced Ryujin Nasukawa, the younger brother of the card headlining star Tenshin Nasukawa. Okubo won the fight by unanimous decision.

Krush Flyweight champion On September 24, 2022, Okubo took part in a 4-man tournament at Krush 141 with the inaugural Krush Flyweight (-51kg) title at stake. In the semifinals he rematched Shohei Nishibayashi and defeated him once again by unanimous decision. Okubo advanced to the final where he faced Daina. The fight was declared a draw after 3 rounds and went to an extension round which Okubo won by split decision to capture the inaugural title.

Okubo vacated his Krush flyweight title on April 14, 2023, in order to move up in weight. Okubo made his debut at 53 kg on June 3, 2023, at K-1 World GP 2023 in Yokohama against Ryunosuke Saito. He lost the fight by extension round decision.

On October 21, 2023, Okubo returned to krush to face Eito Kurokawa at Krush 154. He won the fight by unanimous decision.

K-1 Rui Okubo faced Kazuki Miburo at K-1 World MAX 2024 - World Tournament Opening Round on March 20, 2024. He won the fight by unanimous decision.

Okubo was announced as being part of an 8-man world tournament in the 55 kg division that would see its first round take place on July 7, 2024, at K-1 World MAX 2024 - World Championship Tournament Final. Okubo faced Zhao Zhengdong in the tournament quarterfinals at K-1 World MAX 2024 on July 7, 2024. He won the fight by unanimous decision, with two scorecards of 30–29 and one scorecard of 30–28 in his favor. Okubo faced the two-time K-1 super bantamweight title challenger Masashi Kumura in the final four of the tournament, which was held at K-1 World MAX 2024 on September 29, 2024. He won the fight by unanimous decision, with all three judges awarding him a 30–29 scorecard. Okubo faced the reigning K-1 super bantamweight champion Akihiro Kaneko in the tournament finals. He lost the fight by a second-round knockout.

Okubo faced the reigning Krush Super Bantamweight (-55kg) champion Riamu Sera in a non-title bout at K-1 World Grand Prix 2024 Final on December 14, 2025. He won the fight by unanimous decision, with three scorecards of 30—29 in his favor.

Okubo moved up in weight in order to face Koshiro Takemi in a -58 kg catchweight bout at K-1 World MAX 2025 on February 9, 2025. He won the fight by a third-round knockout, the first stoppage victory of his career.

Okuba faced Shion in a -56 kg catchweight bout at K-1 Dontaku on July 13, 2025. He won the fight by a first-round technical knockout.

Okubo faced Wu Yutong at K-1 World MAX 2025 - 70kg World Championship Tournament Final on November 15, 2025. He won the fight by a first-round knockout.

Okubo challenged the K-1 Super Bantamweight champion Akihiro Kaneko at K-1 World GP 2026 -90kg World Tournament on February 8, 2026. Ahead of the bout, Okubo encountered significant difficulties during his weight cut. At the official weigh-in, he exceeded the contracted limit by 1.3 kg, resulting in the fight being reclassified as a non-title contest. He was also subject to a two-point deduction at the opening of the match, required to use 10 oz gloves in place of the standard 8 oz gloves, and forfeited 30% of his purse to Kaneko. Okubo later stated that he had been experiencing health problems earlier in the month and was hospitalized on February 6 after suffering hearing loss and numbness in his hands and feet. His condition worsened during the final stages of weight reduction, culminating in a loss of consciousness and emergency transport to hospital. Despite receiving treatment and appearing at the weigh-in, he was unable to meet the required weight. Despite holding a clear edge, two judges scored the bout 28–28, resulting in a draw and triggering an extension round. Although Okubo later emerged ahead on the scorecards, his failure to make weight led officials to rule the contest a no-contest.

Titles and accomplishments Professional Krush 2022 Krush Flyweight (-51kg) Champion

K-1 2024 K-1 Super Bantamweight (-55kg) World Tournament Runner-up

Awards 2021 K-1 Awards Best Amateur Athlete 2022 K-1 Awards Rookie of the Year

Amateur 2015 WBC Muay Thai All Japan Jr League -28 kg Champion 2015 WPMF Japan -30g Champion 2016 SMASHERS -30 kg Champion 2016 REBELS Blow Cup Tournament -30 kg Champion 2016 Battle of MuayThai -30 kg Tournament Winner 2016 NJKF Explosion U-12 -31 kg Champion 2016 Suk Wan Kingthong Real Champion Tournament -30 kg Winner 2016 WPMF Japan -35 kg Champion 2017 Windy Super Fight Kick -33 kg Champion 2017 NJKF Explosion U-12 -34 kg Champion 2017 MuayThaiOpen -35 kg Champion 2017 SMASHERS -35 kg Champion 2017 NJKF Explosion U-15 -34 kg Champion 2017 Suk Wan Kingthong Real Champion -34 kg Tournament Winner 2017 WBC Muay Thai All Japan Jr League -34 kg Champion 2017 Shootboxing All Japan -35 kg 2017 WPMF Japan -40 kg Champion 2018 Windy Super Fight Kick -36 kg Champion 2018 Bigbang -37 kg Champion 2018 SMASHERS -40 kg Champion 2018 MuayThaiOpen -40 kg Champion 2018 WBC Muay Thai All Japan Jr League -37 kg Champion 2018 TENKAICHI -40 kg Champion 2018 National Junior Kickboxing Champion 2018 NJKF Explosion U-15 -40 kg Champion 2019 TENKAICHI -45 kg Champion 2019 NJKF Explosion U-15 -45 kg Champion 2019 Bigbang -45 kg Champion 2019 MuayThaiOpen -45 kg Champion & Event MVP 2019 WBC Muay Thai All Japan Jr League -45 kg Champion 2020 K-1 Challenge B-class Tournament -55 kg Winner & Event MVP 2021 Amateur Dageki Kakutougi Japan Cup -55 kg Winner 2021 K-1 All Japan B-class -55 kg Champion & B-class MVP 2021 K-1 Koshien East Japan Tournament -55 kg Winner 2021 K-1 Koshien Tournament -55 kg Winner 2021 K-1 All Japan A-class -55 kg Champion & A-class Event MVP 2021 K-1 Awards Amateur Fighter of the Year

Fight record

Amateur record